21105503572 has 12 divisors (see below), whose sum is σ = 37485894880. Its totient is φ = 10395247896.

The previous prime is 21105503537. The next prime is 21105503603. The reversal of 21105503572 is 27530550112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39375672 + ... + 39376207.

Almost surely, 2^21105503572 is an apocalyptic number.

It is an amenable number.

21105503572 is a deficient number, since it is larger than the sum of its proper divisors (16380391308).

21105503572 is a wasteful number, since it uses less digits than its factorization.

21105503572 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78751950 (or 78751948 counting only the distinct ones).

The product of its (nonzero) digits is 10500, while the sum is 31.

The spelling of 21105503572 in words is "twenty-one billion, one hundred five million, five hundred three thousand, five hundred seventy-two".